Needle-type colloid osmometer

Abstract

A needle-type colloid osmometer is disclosed. This osmometer comprises a hollow needle body having at least one hole at its outer wall and acting as a part of a pressure sensing chamber, a cylindrical semipermeable membrane fitting the needle body therein, and a sampling chamber receiving the needle body with the membrane. The osmometer is usable for measuring colloid osmotic pressure of blood, lymph, body fluid or the like in the fields of clinical pathology, physiology, biochemistry, biology and the like.

What is claimed is: 
     
       1. A needle-type colloid osmometer comprising a hollow needle body constituting at least a part of a pressure sensing chamber filled with a standard solution and having at least one hole at its outer wall, a cylindrical semipermeable membrane fitting said needle body therein so as to seal at least said hole, and a sampling chamber receiving said needle body with said membrane and filled with a sample. 
     
     
       2. A needle-type colloid osmometer as claimed in claim 1, wherein the inner diameter of said cylindrical semipermeable membrane is slightly smaller than the outer diameter of said hollow needle body. 
     
     
       3. A needle-type colloid osmometer as claimed in claim 1, wherein said hollow needle body is an injection needle with a tip opening and is sealed as its tip opening with a detachable plug. 
     
     
       4. A needle-type colloid osmometer as claimed in claim 1, wherein said hollow needle body has 4 to 6 holes at its outer wall.